A SOMACLONAL VARIANT IN 'HEDELFINGER' SWEET CHERRY

Somaclone HS, isolated from a population of regenerated shoots from Prunus avium `Hedelfinger’ leaf explants, exhibited a different pattern of growth and development when tested under different light qualities, in both in vitro and ex vitro conditions. DNA analyses conducted by an ISSR (Interspaced Simple Sequence Repeat) system revealed a polymorphism between the HS somaclone and the wild type propagated by microcuttings. Under white light, proliferating shoots of somaclone HS had reduced apical dominance compared to the wild type. Somaclone HS shoots grown in vitro under blue light had a peculiar bushy habit due to reduced leader shoot growth, a relatively high number of nodes (buds) formed along the stem, and a reduced 'distance from the apex' (expressed as the number of nodes between the shoot apex and the first lateral shoot). Darkness affected chlorophylls a and b accumulation to a greater extent in somaclone HS than in `Hedelfinger’, not only in vitro but also in ex vitro conditions.